Damage Diagnosis for Wind Turbine Blades Based on the Shifting Distance of Characteristic Frequency

Wind turbine blades are the key component of wind turbine. The blades may be damaged by fatigue, wind gusts, or lightening strikes. It is important to detect the damage before the blade catastrophically fails, which could destroy the entire wind turbine. In this paper, a new method is presented for damage diagnosis on wind turbine blades which is developed based on the distance classification rules in pattern recognition. The states of the blades can be identified by measuring the vibration response of one fixed point on the turbine. The blade fault can be therefore determined according to the shifting distance of characteristic frequency in the signal. The results of these studies show that the method can be applied in engineering practice as well as developing a process for structural health monitoring techniques for wind turbine blades.